The present invention is directed to a lower bearing assembly for a turret mooring system which comprises a disconnectable buoy. More particularly, the invention is directed to a bearing assembly which transmits the horizontal mooring loads directly from the buoy to the vessel.
Turret mooring systems are commonly used to anchor a vessel to the sea floor. Disconnectable turret mooring systems typically comprise a buoy which is anchored to the sea floor and which is connectable to a turret that is rotatably supported by the vessel. During operation, the buoy may be hoisted from a submerged position below the vessel and connected to the bottom of the turret to thereby moor the vessel to the sea floor.
The turret is usually supported in the vessel by both upper and lower bearing assemblies. The upper bearing assembly typically comprises a combination axial and radial bearing which is capable of transmitting both the vertical and horizontal mooring loads from the turret to the vessel. The lower bearing assembly usually comprises a radial bearing which transmits only the horizontal mooring loads from the turret to the vessel.
Thus, in conventional turret mooring systems both the upper and lower bearing assemblies are positioned between the turret and the vessel. Consequently, the turret must typically be sufficiently long to extend from the upper bearing assembly to the lower bearing assembly. However, the greater the length of the turret, the more difficult and expensive the turret is to manufacture.